Skip to main content

Full text of "A letter to the Right Honourable Sir Benjamin Hall, bart. : president of the General Board of Health"

See other formats


A 



L E T T E R 

TO 

THE RIGHT HONOURABLE 

SIR BENJAMIN HALL, BART, 

PRESIDENT OF THE GENERAL BOARD OF HEALTH, 



BY 

JOHN SNOW, M.D, 

MEMBER OF THE ROYAL COLLEGE OF rHYSICIANS, AND PRESIDENT OF THE MEDICAL 
SOCIETY OF LONDON. 



LONDON: 

JOHN CHURCHILL, NEW BURLINGTON STREET. 



1855. 



Duke U niversity -Aledical Center Library 



rent 



Coll 



enter 
ection 



Gift of 

Mrs. James H. Semans 



TO THE RIGHT HON. 

SIR BENJAMIN HALL, BART. 



Sir, 

I was ordered, as you are aware, to give evidence 
before the Select Committee on Public Health Bill 
and Nuisances Removal Amendment Bill, of which 
Committee you were the Chairman. I stated my 
opinion that certain useful though offensive trades 
do not cause, or in any way promote the prevalence 
and mortality of cholera, fevers, and other diseases, 
which are communicated from person to person, and 
which, on account of the property of being so com- 
municated, take on very often the form of epidemics. 
I explained the grounds of my opinions as well as 
the opportunity permitted. Although I had pub- 
lished the same opinions on more than one pre- 
vious occasion, and they had received no notice 
except of approval, I have been subjected since 
expressing them to the Select Committee to some 



4 



rather severe attacks, commencing in the newspaper 
press, and continued in the medical journals. 

The writers of these attacks have assumed and 
asserted that the opinions I have expressed on the 
subject of offensive trades are altogether new and 
peculiar. This error might be excused in the editor 
of a newspaper, but in the editors of the two medical 
journals who have given a leader on my evidence it 
is altogether unpardonable. It is only necessary to 
quote the following passage from page 635 of Dr. 
Bancroft's work on Yellow Fever, published in 
London in 1811, in order to show that my opinions 
on this point are at all events not new. 

" The following statement is extracted from a 
letter written to the author by Mr. Lawrence, Ana- 
tomical Demonstrator at St. Bartholomew's Hospital ; 
whose character, talents, and professional acquire- 
ments, have already, at an early period of his life, 
greatly and justly advanced him in the road to 
eminence. 

" ' In a constant attendance at the dissecting room 
of St. Bartholomew's Hospital, for more than ten 
years, I have never seen any illness produced by the 
closest attention to anatomical pursuits, except such 
as might be expected to follow from a similar con- 
finement and application to any other employment. 



5 



" c When it is considered that most of the students 
come from the country, and that many spend much 
time in dissection, being employed also in writing, 
reading, &c, during the rest of the day, it will not be 
a matter of surprise that their health should occasion- 
ally suffer : but the indisposition has never appeared 
to derive any peculiar character from the exposure of 
the subject to putrid effluvia. Of course you will 
except from this observation, the effects which may 
arise from the absorption of noxious matter from 
wounds received in dissection. It has not appeared 
to me that ill consequences of that description follow 
more frequently from the dissection of the most 
putrid, than from that of recent bodies. The follow- 
ing particulars will afford the most complete proof, 
that the exhalations from decomposing animal sub- 
stances are not necessarily injurious to the human 
body. John Gilmore, together with his wife, and 
two sons, lived for ten years in a room under the ana- 
tomical buildings of St. Bartholomew's Hospital. The 
whole family slept, as well as spent the day, in this 
apartment, which received a very small quantity of 
light, in consequence of its single window opening 
against a high wall. The room was at the end of a 
passage, in which several tubs containing bones in a 
state of maceration were generally placed, and with 
which other divisions of the cellars communicated, 



6 



containing large excavations for receiving the refuse 
of the anatomical rooms. The latter were not sepa- 
rated from the passage by any door. 

" ' The animal matters thrown into the receptacles 
last mentioned, are, I believe, converted into adipo- 
cere, and the fetor is consequently not so offensive as 
if they went through the putrefactive process; but 
the whole place was constantly filled with a close 
cadaverous smell, very disagreeable to any persons 
who went down from the fresh air. During the 
whole clay, Gilmore was employed about the dissecting- 
room, in removing the offals, in cleaning macerated 
bones ; in short, in an almost constant handling of 
putrid matters. He always enjoyed good health, was 
fat, and possessed very great bodily strength. He left 
his situation in consequence of an apoplectic attack, 
and died lately, at the age of 69, after two other similar 
affections. His wife survives, enjoying a good state 
of health. Neither of his sons appears to have suf- 
fered from any unwholesomeness of their abode. 
They are both hearty and strong, although they have 
been employed some years in attending the dissecting 
room. But the whole family left the cellar soon 
after the father's first attack.' " 

The above facts, detailed by Mr. Lawrence, agree 
with the experience of all medical men regarding 



7 



dissection, and the bearing of these facts on the mis- 
chief alleged to arise from other occupations connected 
with decomposing animal matters must be very evi- 
dent. I could, indeed, if I had time, quote many- 
passages from trustworthy authorities to prove that 
skin dressing, bone crushing, and other offensive 
trades are not perceptibly injurious to health; but I 
have preferred to select the above passage, because 
the experience and opinion of Mr. Lawrence, who is 
well known to you as an eminent member of the 
Medical Council of the General Board of Health, will 
naturally have more weight with you, than the opinions 
and evidence of others who might be strangers. 

It is hardly necessary to remark that occupations 
which are not injurious to those who follow them, 
cannot, by any stretch of the imagination, be con- 
sidered to do harm to those who merely live in the 
neighbourhood in which the occupations are pursued. 
As the gases given off from putrefying substances 
become diffused in the air, the quantity of them in a 
given space is inversely as the square of the distance. 
Thus, a man working with his face one yard from 
offensive substances, would breathe ten thousand times 
as much of the gases given off as a person living a 
hundred yards from the spot. Currents of air would 
make a difference ; but this would be the average 
proportion of the gases inhaled respectively by the two 



8 



individuals. Therefore, if these gases are supposed to 
act as ordinary poisons, the health of the workman 
ought to be injured ten thousand times as much as that 
of the inhabitant a hundred yards from the factory; or 
if they are supposed to act as specific poisons, having 
the power of reproduction, so that the smallest quan- 
tity might suffice to set up disease, then the chances 
of contracting such disease would be ten thousand 
times greater amongst the workmen, than amongst 
those living at a distance of one hundred yards. 

It is sometimes asserted that workmen become 
inured by habit to offensive trades, and thus escape 
the diseases which attack others at a distance ; but 
they who use this argument forget that those at a 
distance ought by habit to become inured to their 
minute dose as well as the workmen to the larger 
quantity ; and also that the workmen are not inured 
by habit when they fxrst enter on their trades, and 
ought then to be affected by their occupation if it 
really produced fevers and other epidemic diseases ; 
but this is contrary to experience. 

The gases which result from the putrefaction of 
animal substances are capable of causing death, when 
they are breathed in a concentrated form, and it is 
often assumed that this of itself proves that they must 
be more or less injurious in the most minute quanti- 
ties. This, however, by no means follows, for car- 



9 



bonic acid gas causes instant death when not much 
diluted, and yet it is a natural constituent of the 
atmosphere, and is constantly breathed in all parts of 
the world. Carbonic acid gas is not so powerful a 
poison as some of the gases resulting from putre- 
faction ; but then the amount of it always present in 
the air is far greater than that in which the gases 
from putrefying substances are ever met with in the 
streets and houses nearest to any kind of offensive 
factory. 

The editors who have attacked me have apparently 
copied each other's sentiments, and they have as- 
sumed that my opinions respecting offensive trades 
are the consequence of the principles I have endea- 
voured to establish concerning the mode of commu- 
nication of cholera, typhoid fever, and some other 
diseases. But this is an error, for I held the senti- 
ments that I now hold respecting offensive trades, for 
many years before my opinions were formed, on the 
mode of communication of cholera, at the latter part 
of 1848 ; and in this respect I was in no way singular. 
One of the most approved and largely circulated 
works on the Practice of Physic, is Dr. Watson's 
Lectures, which first appeared in the Medical Gazette 
in 1841-2. The following passage will show Dr. 
Watson's opinions with respect to the alleged con- 
nection between fever and offensive effluvia. 



10 



" Again, continued fever has been attributed, with 
great confidence, to a vitiated state of the air, from 
the putrefaction of dead animal and vegetable sub- 
stances. Dr. Bancroft deals with and demolishes this 
error also, showing that, neither the putrid atmos- 
phere of the dissecting-rooms (respecting which you 
must have some personal experience), nor the noi- 
some effluvia from full and ill-conditioned burial 
grounds, nor those to which tallow-chandlers, soap- 
boilers, glue and catgut makers, and the melters of 
whale-blubber, are exposed, nor the foul air of 
sewers and privies, have ever been known to produce 
anything like continued fever. In some parts of 
Essex, near the coast, where the farmers are in the 
habit of manuring their fields with shoals of sprats, 
I have seen large tracts covered with these fish in a 
state of putrefaction. The stench they occasion is 
horrible ; but no disease results. Dr. Chisholm, in a 
paper to which I can only refer, but which I would 
recommend you to look at, in the sixth volume of 
the Edinburgh Medical and Surgical Journal, brings 
forward other, and very satisfactory, instances, to the 
same purpose : from a bone manufactory, near Bitton, 
in Gloucestershire ; from an establishment (now re- 
linquished) on the banks of the Avon, for converting 
the flesh of dead animals into adipocere ; from manu- 
factories for refining sugar, where the blood of 



11 



slaughtered animals is kept for that use by butchers ; 
from the leather-dressing business ; all tending, I 
say, to the conclusion, that air, contaminated by the 
decomposition of animal substances, is not necessarily 
noxious to life ; still less productive of that specific 
disease which we are now considering. The old 
belief, therefore, was unfounded, that the exhalations 
from the dead and putrefying bodies of men and 
horses, lying unburied on the field of battle, are 
capable of producing a pestilence. Many instances 
to the contrary are on record ; one, of an early date, 
is thus stated by Diemerbroek : β€” 'Anno 1642, in 
agro Juliacensi maxima strages facta est, et ad mini- 
mum 8,000 militum occisa fuerunt, prseter majorem 
aclhuc famulorum, etc., numerum : corpora inhumata 
sub dio computruerunt, nulla tamen pestis insecuta 
est.' "β€”Medical Gazette, 1842, Vol. xxx., p. 791. 

Although there is sufficient direct evidence to 
prove that cholera is neither caused nor increased 
by offensive trades,* that circumstance is very much 
confirmed by the facts which I have been able to 
collect in illustration of the mode of propagation of 
cholera ; for it is not reasonable to seek for addi- 

* The Registrar-General's sub-district of Lambeth Church, first 
part, which extends by the river side from Westminster Bridge to 
Vauxhall Bridge, and contains most of the manufactories that are 



12 



tional causes of any phenomenon, when a real and 
adequate cause is known. Thus the itch, owing to 
its being almost exclusively confined to the poor and 
dirty, is more confined to neighbourhoods where 
offensive smells prevail, than typhoid fever is, and 
very much more so than cholera is ; yet no one 
attributes the itch to the gases given off by decom- 
posing animal or vegetable matters, for the simple 
reason that the real and sufficient cause of that com- 
plaint is known. 

It appeared to me that you were not sufficiently 
aware of the bearing that any facts, which should 
establish a distinct and adequate cause of cholera, 
would have on the alleged effect of offensive trades in 
promoting that malady ; for when a member of the 
Select Committee β€” Mr. Wilkinson, I think β€” put a 
question to me respecting the cause of the outbreak 

complained of in Lambeth, suffered only a mortality of 29 persons 
in 10,000, in the epidemic of cholera in 1854, whilst the more 
genteel, open, and thinly peopled sub-districts of Clapham and 
Kennington, in which few factories are situated, suffered as fol- 
lows : Clapham, 103 ; Kennington, first part, 125 ; and Kennington, 
second part, 76 deaths from cholera to each 10,000 inhabitants. 
The sub-district of Saffron Hill, with the open Fleet Ditch flowing 
through it, and the slaughter-houses, knackers' yards, and cat- gut 
factories of Sharp's Alley, on its eastern boundary, suffered the 
lowest mortality from cholera in 1854 of any sub-district in London 
except one. The mortality of the Saffron Hill sub-district was 
only 5 in 10,000, whilst that of London altogether was 45, and 
that of the fashionable Belgrave sub -district was 60 in 10,000. 



13 



of cholera near Golden-square, you did not allow it 
to be answered, although, undoubtedly, the late 
epidemic of cholera was the cause of the bills being 
framed which are now before Parliament. 

The absence or defect of drainage, undoubtedly, 
assists very much in the propagation of many epi- 
demic diseases, and as defective drainage very often 
occasions offensive smells, the editors of whom I com- 
plain have arrived at the short and easy conclusion 
that any trade or manufacture, which gives rise to an 
offensive odour, must also promote disease. The 
matters, which it is the purpose of drainage to re- 
move, contain all that comes from the sick, as well as 
the healthy part of the community, and, when they are 
not properly removed, they permeate the ground, and 
pollute the pump-wells and other supplies of water ; 
and, in this way, as I have elsewhere adduced a good 
deal of evidence to prove,* several epidemic diseases 
may be propagated ; the morbid matter of each 
disease reproducing its own specific malady. There 
are also other ways more gross and material than a 
mere odour, by which the absence of proper drainage 
aids in the spread of disease. On the other hand, 
occupations connected with the skins, bones, or fat of 
dead animals, cannot in any way assist in conveying 

* On the Mode of Communication of Cholera. 



u 



the morbid matter of disease from the sick to the 
healthy. 

I am, of course, no defender of nuisances, but 1 
consider that if a trade is more offensive than it ought 
to be, or is conducted in a place where it has no 
right to be, it might be proceeded against by the 
ordinary laws as a nuisance, without using the word 
pestiferous, or otherwise dragging in and distorting 
the science of medicine. 

Some of the manufacturing processes which give 
rise to offensive smells, are not only a source of wealth 
in themselves, but are highly useful to agriculture. 
These are circumstances that would, at one time, 
have been thought worthy of consideration, but, how- 
ever desirable it may be that commerce and agricul- 
ture should not be injured on mistaken grounds, it is 
still more important that the real causes which affect 
the health of the community should be ascertained, 
and that epidemics should not be attributed to a 
wrong cause, for I have previously shown* that great 
increase of disease has several times been occasioned 
by presumed sanitary measures. 

I have of course not written this letter in the way 
of personal complaint against the editors by whom I 
have been attacked. My reason for writing it is, that 
I have an impression that the editors in question 
* Opus cit., p. 100 and 136. 



15 

have really expressed the sentiments of the majority 
of the persons who have paid little attention to the 
subject, but are more likely to influence legislation 
than careful and industrious observers. 

I have the honour to be, Sir, 

Your obedient servant, 

JOHN SNOW, M.D. 

Sackville Street, July 12th, 1855. 



LONDON: 

T. RICHARDS, 87, GREAT QUEEN STREET.